JP2541893B2 - Continuous foaming type rubber sheet manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a continuous foam type rubber sheet, and more specifically, it can be applied with a small amount of cosmetics to reduce the waste of the cosmetics and to apply it evenly and smoothly. The present invention relates to a method for producing a continuous foam type rubber sheet having a uniform sheet thickness and excellent feel. The present invention is
Used for cosmetic applicators.

[0002]

2. Description of the Related Art A conventional first makeup applicator is N
It is known that it is made of rubber such as BR, and that the closed cell portion and the semi-open cell portion are integrally formed, and that the open cell portion has an increased open cell rate from one side close to the closed cell portion to the other side. (JP-A-62-179404). Also,
As the second makeup applicator, the application part is made of polyurethane and is formed by heating and compressing it (Jitsuko Sho 6).
No. 0-33863), the third makeup applicator comprises a core material made of rubber latex or the like and a microporous wet polyurethane skin material adhered to the surface thereof (JP-A-62- (148,608 publication) is also known.

[0003]

Although the first makeup applicator is manufactured by heating and compressing it, it converts open cells to closed cells by heating and compression. It cannot be used as the coating surface of the material, and the diameter of the bubbles is still too large on the surface of the other open-cell portion which is the coating surface. Further, the second and third makeup applicators have a three-dimensional network structure even though the application surface is made of a polyurethane material and is an open cell, and even if the cell diameter is small, It has the drawbacks that the amount of cosmetics retained is too large, the absorption rate of cosmetics is too high, and that polyurethane materials cannot provide an excellent feel such as NBR. Even if it is formed by heating and compressing it like the second makeup applicator, since the wall thickness remains thin, the amount of cosmetics retained is still the same.

Further, the conventional open-cell type rubber sponge sheet such as NBR has a large cell diameter, and therefore has a drawback of excessively absorbing cosmetics. Therefore, it is conceivable that the sponge sheet is thinly processed to be bonded to another material to manufacture a makeup applicator. However, in this case, there are the following problems. (1) It is very difficult to perform thin skiving due to stickiness, and it is necessary to increase hardness for thin skiving, but in this case, the texture is impaired. (2) There are variations in the thickness of the gap, and
It is difficult to perform skiving to a thickness of mm or less (particularly 1.5 mm or less). (3) Since the viscosity varies depending on the cosmetic, it is difficult to adjust the proper content of the cosmetic under the above conditions.

The present invention overcomes the above-mentioned drawbacks and can produce a continuous foaming type rubber sheet such as NBR and a thin rubber sheet having a thickness of 2 mm or less, and is saturated with a small amount of cosmetics to reduce the waste of the cosmetics. It can be applied to the uniformly smooth, sheet thickness is uniform, and excellent in touch continuous
We can manufacture foamed rubber sheets (sheets of material such as fossil materials)
The purpose is to provide a method of

[0006]

A method for manufacturing a continuous foaming type rubber sheet according to the first aspect of the present invention is a continuous foaming type rubber sheet in which a pair of upper and lower heating plates or heating rollers are used in the method for manufacturing a continuous foaming type rubber sheet. It is characterized in that the material is pressed under heating or heated and then pressed to reduce and adjust the size of the continuous foam cells. The method for producing the same rubber sheet according to the second aspect of the present invention is the same as the method for producing a continuous foam type rubber sheet, wherein a continuous foam type unvulcanized rubber sheet material is pressed under heating by using a pair of upper and lower heating plates or heating rollers. It is characterized in that it is heated after being pressed to be vulcanized, and at the same time, the size of the continuous foamed cells is reduced and adjusted.

A flexible foaming base material layer is bonded to the back side of a continuous foaming type thin rubber sheet having a thickness of 2 mm or less, which is manufactured by the manufacturing method of the first or second invention, and is used for cosmetics.
An applicator can be manufactured . If the sheet thickness exceeds 2 mm, the amount of cosmetics retained becomes large, and the cosmetics are wasted, and it is difficult to manufacture cosmetics with a thickness of 2 mm or less (particularly 1.5 mm or less) by ordinary skiving. That's why.

In the above, the sheet and the foamed base material layer may be bonded with an adhesive, and the foamed base material layer may be formed on the sheet by integral foam molding. It can be assumed to be present.
In the former case, the adhesive layer becomes a non-liquid-permeable film, and the cosmetic material does not soak into the base material layer, so that the usage amount of the cosmetic material can be further reduced. The latter is a flexible foaming base that does not use an adhesive and arranges and applies the raw material that will become the flexible foaming base directly on the rubber sheet and foams it in a predetermined mold to integrally form a flexible foaming base. It can be manufactured by forming a material layer (vulcanization adhesion). This is because the surface layer and the base material layer are excellent in unity, and therefore the bondability and the feeling of unity are excellent, and at the interface between both layers, some of the bubbles in the surface layer are blocked by the base material layer cell, so that the makeup is improved. The amount of bleeding into the substrate layer is also reduced. . The "rubber" in the above is made of so-called rubber such as NBR, SBR or NR, and is not made of polyurethane material.

[0009]

In the production method of the present invention, a rubber sheet having a desired sheet thickness, pore diameter, porosity and the like can be produced by pressing the continuous foaming rubber sheet material under heating.
Therefore, the size of the continuous foamed cell can be easily reduced, and the size can be adjusted by changing the compression condition, and the sheet having a smooth surface with a predetermined thickness (especially 2 mm or less) can be obtained. A thin sheet can be manufactured easily and reliably.

The sheet is made of rubber and has a thickness of 2 mm or less. Further, as shown in FIGS. 2 to 5, the wall thickness (A) does not change much after compression as compared with that before compression, and the bubbles are flattened after being compressed. Therefore, the cosmetic can be easily retained and discharged, and the amount of the cosmetic retained is appropriately small, so that the cosmetic is less wasted. Further, the cosmetics can be adjusted appropriately, the cosmetics can be applied evenly and smoothly, and the feel during use is superior to that of the polyurethane material. still,
In the case of polyurethane foam, as shown in FIGS. 8 to 9, the wall thickness is small and the bubble ratio (bubble volume) is still large even after compression.

[0011]

The present invention will be described below in detail with reference to examples. Example 1 (1) Production of compressed sheet Example 1 First, NBR continuous foaming type sheet material [250 mm × 1
50 mm × 2.2 mm or 2.6 mm (thickness)] 1 is prepared. A micrograph of the surface of this sheet material (having a thickness of 2.2 mm) 1 is shown in FIG. 2, and a micrograph of its cross section is shown in FIG. Then, the sheet material 1 is arranged between the pair of heating plates 3 of the apparatus shown in FIG. The heating plate 3 has a heating medium (for example, a heater) 31, which heats the heating plate 3 to 150 ° C. A cylinder 4 is provided on one of the heating plates 3 so that it can move up and down.

By operating the cylinder 4, the heating plates 3, 3
Was moved to the side of the sheet material 1, and the sheet material 1 was pressed from both sides. Then, the sheet material 1 was compressed to have a predetermined thickness described below and heated at 150 ° C. for a predetermined time. The molding conditions for the material sheet having a thickness of 2.2 mm are as follows: finished thickness 0.7 mm (compressibility: 3
2%), the heating time is 1 minute, and the material sheet having a thickness of 2.6 mm has a finish thickness of 0.8 mm (compressibility: 31%) and a heating time of 0.5 minutes.

Then, the compressed state of the pair of heating plates was released, the heated rubber sheet 2 was taken out, and cooled at room temperature to prepare two types of compressed sheets. The former is an example product N
o. No. 1 and the latter are the example product Nos. Set to 2. This No. 1
The micrograph of the surface of the thing is shown in FIG. 4, and the micrograph of the cross section is shown in FIG. According to the results of this photograph, the bubble diameter before compression is 80 to 200 μm, which is crushed by the compression and the cell thickness becomes thicker, and the cells spread laterally, showing a continuous bubble state.

Comparative Example 1 Foamed polyurethane sheet [foamed with polyester polyol and tolylene diisocyanate, foaming ratio: 33 times, size: 250 mm × 150 mm ×
2.2 mm (thickness)] is prepared. A micrograph of the surface of this sheet is shown in FIG. 6, and a micrograph of its cross section is shown in FIG.
Shown in Then, this sheet is used as an example product No. In the same manner as in 1 (same apparatus, same compression ratio), compression was performed to produce a compressed sheet. A micrograph of the surface of this compressed sheet is shown in FIG.
Fig. 9 shows a micrograph of the cross section. According to the result of this photograph, although the bubble is crushed by compression and spreads laterally, the cell thickness is small, so that the pore diameter and the porosity are still large.

(2) Performance evaluation Tactile evaluation Example product No. When actually touched with the hands, the surfaces of Nos. 1 and 2 did not lose the feel of the raw material, and had a moist feel.

Puff Performance First, the product No. A total of four types of foamed sheets, 1 [two types before compression (No. 1A) and after (No. 1B)] and the comparative product [two types before compression (No. 3A) and after (No. 3B)] To prepare. 40x40 of each sheet
1 mm (illustrated in FIG. 10) of 1 mm is placed on a blank sheet. Then, 2 drops (about 0.04 g) of the liquid cosmetic are dropped on each of the sheets. One minute after that, the spread of the cosmetic after dropping, the degree of penetration into the interior, whether to pass through the sheet, and the spread (coating performance) when applied were examined, and the results are shown in FIG. 10.

As a result, the product No. In 1A, the spread (L) 1 minute after the dropping of the cosmetic is about 13 mm,
Almost nothing left on the surface, that is, most of it penetrated into the inside, but there was no liquid leakage from the lower surface of the sheet (that is, the cosmetic material did not adhere to the underlying paper). It was confirmed that when this was pressed, liquid leakage occurred from the lower surface of the sheet, and the state was an open cell state. On the other hand, the compressed No. In 1B, the cosmetic still remained on the surface even after 1 minute and spread a little to the side, so that the spreading diameter after 1 minute was 15 as shown in FIG.
It became a little larger than mm. Even after several minutes (not to mention 1 minute later), there was no liquid leakage from the lower surface of the sheet. In this case as well, it was confirmed that the cells were in the open-cell state by pressing the same.

On the other hand, the comparative product No. In 3A, when it was dropped, it almost did not spread to the side and immediately penetrated into the inside, and after 1 minute (within 1 minute), the cosmetic material adhered to the paper of the underlayment. In addition, the comparative example product No. Also in 3B, the cosmetics immediately reached the underlay paper. The amount of cosmetics adhered to this paper is the same as No. 3B was a little more frequent. The spread diameter after 1 minute was 10 to 11 mm as shown in FIG. Even if compressed, the permeation rate hardly changes.

Further, spread in coating (coating performance)
Was examined for each sample, and the results are shown in FIG. Specifically, this test method is one in which the above two drops of cosmetics have been dripped (shown in the left column of FIG. 9) on paper,
It was applied to the face while turning it by hand, and the spread (right column in FIG. 9) after the cosmetic was cut off and application was no longer possible was evaluated. According to this result, the example product No. 1B has the widest range (diameter 55-60
mm) and then the comparative product N before compression
o. It was 3 A (40-50 mm). On the other hand, the example product No. before compression. In 1A, the application range is about 30 to 40 mm, and No. Less than 1B.

From the above, the product No. It is shown that the compressed product of 1B penetrates sufficiently into the inside, and the permeated cosmetic material is more likely to come out from the surface than 1A.
In addition, compared with the comparative example product, there is no cosmetic that passes through the inside of the sheet even if it is as thin as 0.7 mm.
A small amount of cosmetics can be effectively used. In addition, the comparative example product No. before compression. 3A also has a relatively large coating area (4
(0 to 50 mm), many cosmetics pass through, and the permeated cosmetics are too easy to come out. That is, when squeezed, this cosmetic material oozes out, making it difficult to apply it smoothly and smoothly. On the other hand, Example product N
o. Since 1B does not stain even when the permeated cosmetic is squeezed, it can be applied smoothly and smoothly.

(3) Fabrication of puff (Example 2) Example No. 1 manufactured in Example 1 1 by using FIG.
A makeup applicator (hereinafter referred to as a puff) including a base material layer 21 and a surface layer 22 adhered / formed thereon as shown in FIG.
I made 2. That is, the rubber sheet is continuously foamed into NBR.
A base material sheet (thickness: 8 mm) is joined with an adhesive (urethane adhesive or rubber adhesive) to form a track shape (major axis;
About 50 mm, minor axis; about 40 mm), and then
The end surface was polished to obtain a puff. Since the surface layer 21 of this puff is made of the NBR rubber system described in Example 1, it has excellent tactile sensation and excellent puff characteristics as described in Example 1.

In the present invention, the present invention is not limited to the specific embodiments described above, but may be variously modified within the scope of the present invention in accordance with the purpose and application. That is,
By selecting the thickness, compression rate, heating temperature, heating time and the like of the compression sheet material, the thickness of the final rubber sheet or the size of the bubble diameter can be freely set.

Further, the rubber sheet material may be not vulcanized but unvulcanized. The processing conditions in this case can be variously selected depending on the purpose and application. For example, (1) you may compress while heating (for example, 80-100 degreeC), and (2) predetermined thickness (for example, 0.5-1.
(0 mm), then move to a heating furnace etc. and heat here at 80 ° C for about 2 hours or at 100 ° C for about 1 hour to vulcanize and fix the cell to a predetermined size. You can also In the former case, the cells on the surface side are smaller and non-uniform as compared with the inside of the cell, but in the latter case, cells having a substantially uniform surface layer and inside can be formed. The base material layer in the puff is
Not only the continuous foaming type but also the independent foaming type can be used, and the shape, size, thickness, bubble diameter and the like in that case are not particularly limited. Furthermore, the material is not limited to polyurethane foam, but N
Rubber such as BR can be used.

[0024]

According to the manufacturing method of the present invention, the size of the continuous foamed cell can be easily reduced and the size can be adjusted, and the sheet having a desired thickness (especially, a thin sheet of 2 mm or less) can be obtained. The sheet can be manufactured easily and surely. Further, according to this manufacturing method, the sheet thickness is uniform,
Saturated with a small amount of cosmetics to reduce the waste of cosmetics, can be applied smoothly and evenly, and has an excellent feel.
That is, a sheet having excellent performance as a cosmetic applicator can be produced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing state of a continuous foaming thin rubber sheet in Example 1.

FIG. 2 is a micrograph showing a crystal structure on a surface of a rubber sheet material used in Example 1.

3 is a micrograph showing a crystal structure in a cross section of the rubber sheet material shown in FIG.

FIG. 4 is a micrograph showing a crystal structure on a surface of a compressed sheet produced by compressing the rubber sheet material shown in FIG. 2 under heating.

5 is a micrograph showing a crystal structure in a cross section of the compressed sheet shown in FIG.

FIG. 6 is a micrograph showing a crystal structure on the surface of a polyurethane sheet material used in a comparative example.

7 is a micrograph showing a crystal structure in a cross section of the polyurethane sheet material shown in FIG.

8 is a micrograph showing a crystal structure on the surface of a compressed sheet produced by compressing the polyurethane sheet material shown in FIG. 6 under heating.

9 is a micrograph showing a crystal structure in a cross section of the compressed sheet shown in FIG.

FIG. 10 is an explanatory diagram showing the spread of the cosmetic after dropping and the spread after application in Example 1.

FIG. 11 is a perspective view of a puff according to the second embodiment.

[Explanation of symbols]

1; continuous foam type rubber sheet material, 2; puff, 21; surface layer, 22; substrate layer, 3; heating plate, 4; cylinder.

Claims (2)

(57) [Claims] 1. A method for producing a continuous foam type rubber sheet, wherein a continuous foam type rubber sheet material is heated under pressure or heated and then pressed using a pair of upper and lower heating plates or heating rollers to form a continuous foam type cell. A method for producing a continuous foam type rubber sheet, which comprises reducing and adjusting the size. 2. A continuous foaming type rubber sheet manufacturing method, wherein a continuous foaming type unvulcanized rubber sheet material is pressed under heating or heated after pressing using a pair of upper and lower heating plates or heating rollers, and then heated. A method for producing a continuous foam type rubber sheet, which comprises vulcanizing and reducing and adjusting the size of a continuous foam cell.